Method of operating a four-stroke internal combustion engine and internal combustion engine for carrying out this method

Abstract

A method of operating a four-stroke internal combustion engine of the carburator or fuel injection type, with one or several reciprocating pistons or one or several rotary pistons wherein during the intake movement of the one or the several pistons an additional gaseous or liquid or gas-liquid mixture fluid is introduced into the cylinder working space through a cylinder side wall aperture in the vicinity of the piston to establish a layer charge overlying the piston. The introduction of this fluid may be effected by suction effects caused by the piston movement. The amount of fluid supplied may be controlled in dependence upon combustion pressure and/or exhaust gas composition. The internal combustion engine includes an aperture in a cylinder wall in communication with a fluid source whereby this aperture is adapted to be obstructed or exposed by the moving piston to control the admission of the additional fluid. Between the aperture and the fluid source may be provided control valve means.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. An internal combustion engine comprising: cylinder means; piston means operably reciprocable within said cylinder means; inlet means for introducing a combustible fuel-air mixture into said cylinder means; ignition means for igniting said mixture; exhaust means for removing combustion gases from said cylinder means; aperture means defined to extend in flow communication with said cylinder means; source means for supplying an additional fluid into said cylinder means through said aperture means; valve means interposed between said source means and said aperture means for controlling the flow of said additional fluid therebetween; sensing means for sensing combustion pressure within said cylinder means; valve control means responsive to said sensing means for controlling operation of said valve means in accordance with the sensed value of combustion pressure within said cylinder means; means for sensing the composition of said combustion gases in said exhaust means; and further valve control means responsive to said composition sensing means for controlling jointly with said valve control means operation of said valve means in response to sensed composition of said combustion gases. 
     
     
       2. An internal combustion engine according to claim 1 wherein said cylinder means comprise internal wall means defining combustion chamber means and wherein said sensing means comprise means defining a portion of said internal wall means. 
     
     
       3. An internal combustion engine according to claim 2 wherein said means defining a portion of said internal wall means comprise yieldable means resiliently movable in response to combustion pressure within said combustion chamber means. 
     
     
       4. An internal combustion engine according to claim 2 wherein said means defining said portion of said internal wall means comprise diaphragm means. 
     
     
       5. An internal combustion engine according to claim 2 wherein said means defining said portion of said internal wall means comprise spring biased piston means. 
     
     
       6. An internal combustion engine according to claim 1 wherein said source means include compressor means for supplying said additional fluid under pressure. 
     
     
       7. An internal combustion engine according to claim 1 wherein the quantity of additional fluid supplied through said aperture means is controlled by said valve control means in dependence upon said sensed values of combustion pressure. 
     
     
       8. An internal combustion engine according to claim 1 wherein the quantity of additional fluid supplied through said aperture means is controlled by said further valve control means in dependence upon said sensed composition of said combustion gases. 
     
     
       9. An internal combustion engine according to claim 1 wherein said additional fluid is a liquid. 
     
     
       10. An internal combustion engine according to claim 1 wherein said additional fluid comprises a mixture of water and oil and wherein said oil comprises between about 1/50th and 1/100th of said mixture. 
     
     
       11. An internal combustion engine according to claim 1 wherein said additional fluid comprises a mixture of water and alcohol and wherein said alcohol comprises between about 1/10th and 1/3rd of said mixture. 
     
     
       12. An internal combustion engine according to claim 1 wherein said composition sensing means comprise a probe arranged in said exhaust means adapted to monitor combustion gas composition therein and wherein said further valve control means include signal transmitting means connected to said probe and adapted to operate said valve means. 
     
     
       13. An internal combustion engine according to claim 2 wherein said aperture means comprise at least one aperture extending through said internal wall means and having a diameter of about 10 mm. 
     
     
       14. An internal combustion engine according to claim 1 wherein said cylinder and piston means comprise a plurality of individual cylinders and pistons, wherein said aperture means comprise at least one aperture extending into each of said cylinders, and wherein all of said apertures are in joint communication with a manifold, said valve means comprising an adjustable throttle assembly mounted in said manifold.